Erosion & Sediment Control

Silt Fences and Super Silt Fences temporarily impound sediment laden runoff, reduce velocities and allow sediment to settle out of the water.

Geofabrics offer all required Silt and Super Silt Fence components, installation tools, and accessories.

Silt Fence

Silt Fences are geotextile fabrics used above ground to retain sediment and avoid silt pollution in rivers, drains, and sensitive environments. Silt Fences are a requirement to be used around construction and earthworks sites to prevent the silt running off the construction zone in an uncontrolled manner, polluting our waterways.

Super Silt Fence

The Super Silt Fence has a double layer of geotextile and additional wire mesh with increased strength for treating larger catchment areas. The Super Silt Fence is used in applications where there will be excessive pressure on the fence due to high water concentration from large catchments.

Silt Socks, Sediment Control Tubes, and other filled containers are lightweight barriers for diverting or filtering water so sediment drops out. They have a variety of applications for controlling sediment, including:

• Intermediate or perimeter sediment control through retention or filtration of runoff
• Control and direct overland flow
• Stockpile containment
• Channel flow control using check dams to reduce water velocity
• Drain protection

Entry or exit points of a construction site should be stabilised to prevent access points from becoming sources of sediment, as well as to minimise dust generation and areas of disturbance.

We recommend that access points incorporate a geotextile separator over the subgrade followed by a suitable depth of aggregate to support vehicle traffic.

Potential eroded sediment from stockpiles and cut faces can be contained at the source, or controlled as runoff.

At the source, lightweight geotextile is used as a temporary measure to mitigate rain and sheet flows from eroding the exposed surface.

Bidim® Soil Cover is a lightweight geotextile ideal for temporary cover of soil bunds, stockpiles and cut batters providing temporary sediment control, erosion protection and dust control on site. It can also be used for lining of low velocity temporary (≤12 months) clean water diversion channels and sediment pond spillways as per Regional Council Guidelines.

Polythene should only be used on very small areas or very short durations.

Temporary clean or dirty water diversion channels and flumes are lined specifically when slopes are steeper than 3H:1V for flumes or if velocities exceed 1m/s in channels.

Geotextiles are a quick and easy-to install option for lining. Often two layers are required. This is usually a non-woven filter fabric to mitigate fines movement and water flows under the structure, and a woven top layer for impermeability. Woven layer is normally placed under non-woven layer.

Decants

Floating decants are used in sediment retention ponds (SRPs) and in decanting earth bunds (DEBs) to drain the cleaner water at the top of the pond while maximising sediment deposition.

Decant kitsets (100mm) for Sediment Retention Ponds (SRPs) and Decanting Earth Bunds (DEBs) are supplied as drilled and assembled “T” bars with the full range of fittings ready to be put together on site. Additional accessories including PVC connectors, flexible coupler, steel Y posts, extension kit and rope.

Rain Activated Dosing System

The Rain Activated Chemical Dosing System is an important step in the treatment of a Sediment Retention Pond (SRP) storm water run-off to ensure the discharge meets consent conditions for discharge and any impact on the environment is minimal. Geofabrics, in partnership with Reel Blue Environmental, supply an innovative compact RADS design offering refinements over the original “Floc Shed”.

Emergency Spillways

Emergency spillways are incorporated into Sediment Retention Ponds and Decanting Earth Bunds to safely discharge excess water during a large storm event. Bidim® A14 nonwoven geotextile can be used to stabilise the emergency spillway and as a level spreader.

Concrete Canvas® (CC) is a flexible, concrete filled geosynthetic, that hardens on hydration to form a thin, durable, waterproof and fire-resistant concrete layer. Essentially, it is concrete on a roll. CC allows concrete construction without the need for plant or mixing equipment, you simply add water.

CC lined drainage channels prevent weed growth, silt generation and erosion, reducing maintenance requirements and costs. CC is 5 times as abrasion resistant as standard OPC concrete, has excellent chemical resistance, good weathering performance and will not degrade in UV. Available in batched, man-portable rolls, CC can be installed for applications with limited access and comes ready to use – no mixing, measuring or compacting required. CC is BBA certified with a durability in excess of 120 years when used in erosion control applications.

Geofabric site containers offer you the convenience of having an Erosion & Sediment Control product supply store onsite for your convenience. This saves you time and money with consignment and pre-purchase options available.

Flexible availability 

• A Geofabrics team member will be responsible for stocktaking and organising the replenishment of your containers.
• You can have containers available at multiple stages throughout your site. We’ll work with you to ensure the correct product at the correct quantities are available when you need them.

Cost control

• You will have complete control of all purchasing. Stock is used if and when you need it, and you’ll know when and where product is being used to apply the correct cost coding.

Reduce downtime

• All your team members have to do is fill out the container specific book provided when collecting goods and Geofabrics do the rest. No need for multiple order numbers throughout the month.
• No waiting for deliveries or working within the constraints of a supplier’s business hours.